<?php
/**
 * Created by PhpStorm.
 * User: lenovo
 * Date: 2016/10/10
 * Time: 20:29
 */header('Content-type:text/html;charset=utf-8');
function getFileExt($path){
    $ext = substr($path, strrpos($path,'.') +1);
    return $ext;
}
$path = 'C:\images\apple.jpg';
$ext = getFileExt($path);
echo "<p> 文件路径: $path </p>";
echo "<p> 文件后缀: $ext </p>";